Modern vehicle doors are thin, minimizing the space available for a window regulator, and the doors have a smooth curved outer surface in which the windows when closed are substantially flush with the outside door surface. The windows and the doors in such vehicles are not flat but have curvature; when the windows are opened they often require more space between the inner and outer panels of the door and thus further restrict the amount of space remaining for the regulator mechanism.
In order to mount the regulator mechanism in the available space, to control the path of the window and to minimize the upper opening between the inner and outer door panels, it is desirable to impart a nominally horizontal component of window movement during the final closing movement. That is, when the window is nearly closed it moves upward and outward to the desired flush position.
Window closing movements in the upward and outward direction have long been known and various camming mechanisms have been proposed to achieve that result. U.S. Pat. No. 1,206,052 to Ternstedt uses a slotted cam plate with a compound curvature and a chain-driven cam follower to guide the window movement simultaneously upwardly and outwardly and then downwardly to finally close the window.
U.S. Pat. No. 2,979,327 to Swanson et al discloses a regulator mechanism which is very space consuming, but achieves substantially full upward movement followed by outward movement of the WindoW. That mechanism employs dual guide tracks on each side of the window with a follower wheel in each of the four tracks, two of the tracks having outwardly turned paths to push the window outward when the follower wheels reach the turns in the tracks.
U.S. Pat. No. 4,819,377 to Bauer et al discloses a single track regulator having a slot with a bifurcated upper end. A pulley with two projecting pins engaged in the slot guides upward movement in the track. A drive cable is wrapped around the pulley to pull the pulley along the track and to impose a moment on the pulley so that the pins are driven into the bifurcated slot portions to rotate the pulley during the final upward closing movement. The pulley is drivingly coupled to the window through a helical cam which moves the window outward when the pulley rotates so that the path of the window has both upward and outward components at the time of closing.